KR20020047714A - Resist Composition For Over-Coat - Google Patents

Abstract

PURPOSE: Provided is a resist composition for overcoat having high heat resistance, high transparency, high residual membrane, high smoothness, and pattern stability. CONSTITUTION: The composition is prepared by the steps of (i) adding polyfunctional monomers corresponding to 50-500 wt% of total resin solid to two binder resin represented by formula 1 and formula 2; and (ii) adding 0.1-50 wt%(based on total resin solid) photopolymerization initiator, 0.1-10 wt% of silicon based compound containing epoxy group, 0.1-3 wt% of composition comprising known photosensitizer, thermal polymerization inhibitor, antifoaming agent, leveling agent, and so on, and solvent. In the formula 1 and 2, X represents hydrogen or a methyl group, Y1 represents an alkyl group or a hydroxyalkyl group having C2-C16.

Description

Resist Composition For Over-Coat

The present invention relates to a resist composition for overcoat, and more particularly, 0.1 to the total resin solid content of two types of binder resins of general formulas (1) and (2), multifunctional monomers, photoinitiators, silicone additives, organic solvents, etc. as main components. It has high heat resistance, high transparency, high residual film rate, high flattening rate and pattern stability prepared by adding a composition containing a mixture of components such as a known photosensitizer, a thermal polymerization inhibitor, a leveling agent and an antifoaming agent corresponding to 3% by weight. It relates to a resist composition for overcoat.

TFT-LCD is one of the fastest growing flat panel display devices and is expected to lead the display device market in the future. The large area of the TFT-LCD is accompanied by the enlargement of the glass currently used and the flattening of the color filter layer has to be solved accordingly. Therefore, in order to achieve a large area of the TFT-LCD, it is essential to develop an overcoat material for flattening the color filter layer.

Currently, the overcoat material uses the color filter resist for TFT-LCD as it is, and the color filter resist mainly uses acrylic resin as the base, and has excellent coating property.However, when overcoat on the color filter layer due to volume shrinkage after curing, The difference in the thickness of the cured coating film becomes large, and thus, the flattening also decreases, and in the case of the acrylic binder containing no aromatic substituent, the glass transition temperature of the overcoat is lowered after curing, thereby deteriorating various mechanical properties. . In addition, in the case of an acrylic resin including an aromatic substituent, the transparency of the overcoat is degraded as the resist film is colored after the photocuring with time, thereby degrading the performance of the TFT-LCD. As part of an ongoing effort to solve such a problem, the applicant of the present invention, in the Republic of Korea Patent Application No. 2000-38041, an acrylic binder represented by the following general formula 1 having a bulky alicyclic structure instead of an aromatic group Resin was used to greatly improve glass transition temperature, heat resistance and transparency. However, when the binder resin of the general formula 1 is used alone, the double bond of the binder resin increases the compatibility with the multifunctional monomer and participates in the photopolymerization to increase the strength of the pattern, but the adhesion with the glass is poor and the pattern is fragile ( brittle) There is a problem that the lateral pressure is weak.

The present invention is to solve the problems of the prior art as described above, the general formula 2 having an aromatic structure in the acrylic binder resin and side chain represented by the general formula 1 having a bulky alicyclic structure instead of an aromatic group The present invention was completed by increasing the glass transition temperature of the resin using a mixture of an acrylic binder resin represented by and obtaining uniform curing through the entire film to improve pattern stability and maintain high resolution.

After all, the present invention is a known photosensitizer corresponding to 0.1 to 3% by weight of the total resin solid content of the two components of the general formula (1) and (2), binder resin and multifunctional monomer, photoinitiator, silicone additive, organic solvent, etc. It is an object to provide a resist composition for overcoat having high heat resistance, high transparency, high residual film ratio, high flatness and pattern stability prepared by adding a composition comprising components such as a thermal polymerization inhibitor, a leveling agent and an antifoaming agent. .

It is another object of the present invention to provide a structure of a binder resin that can be used in a resist composition for overcoat having high heat resistance, high transparency, high residual film rate, high flattening rate and pattern stability, and a composition ratio thereof.

Still another object of the present invention is to provide a multifunctional monomer that can be used in a resist composition for overcoat having high heat resistance, high transparency, high residual film rate, high flattening rate and pattern stability, and a composition ratio thereof.

It is still another object of the present invention to provide a photoinitiator and a composition ratio thereof that can be used in a resist composition for overcoat having high heat resistance, high transparency, high residual film ratio, high flattening ratio, and pattern stability.

It is another object of the present invention to provide a silicone-based compound comprising an epoxy group that can be used in a resist composition for overcoat having high heat resistance, high transparency, high residual film rate, high flattening rate and pattern stability.

Another object of the present invention is to provide an organic solvent having excellent compatibility with binder resins.

1 is a schematic view of a color filter for TFT-LCD using an overcoat

2 is a thermogravimetric decomposition of the overcoat resist after UV curing

3 shows the transparency of the overcoat resist after UV curing

4 is a pattern photograph of a resist composition for overcoat

♣ Explanation of symbols for the main parts of the drawing ♣

1: color filter 2: black matrix

3: Use of resist composition for overcoat of color filter of TFT-LCD

Hereinafter, the present invention will be described in more detail.

In the resist composition for overcoat for achieving the object of the present invention, a multifunctional monomer corresponding to 50 to 500% by weight of the total resin solids is added to the two kinds of binder resins represented by the following general formulas (1) and (2), 0.1 to 50% by weight of photoinitiator of the resin solids; Silicone-based compound containing 0.1 to 10% by weight of the epoxy group of the total resin solids; A composition in which components such as known photosensitizers, thermal polymerization inhibitors, antifoaming agents, and leveling agents corresponding to 0.1 to 3% by weight of the total resin solids are mixed; And by adding a solvent.

One resin of the binder resin that can be used in the present invention is characterized by the use of a copolymer comprising a combination of a monomer having a double bond and a monomer containing a carboxylic acid in the structure of the general formula (1).

[Formula 1]

X represents a hydrogen atom or a methyl group, Y ¹ represents an alkyl group or a hydroxyalkyl group having 2 to 16 carbon atoms, and Y ² represents the following formulas (I) to (XX).

In formulas (I) to (XX), R ₁ is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ is a residual group of hydrocarbon having 1 to 10 carbon atoms , R ₄ is hydrogen or a methyl group, R ₅ is an alkylene group with from 1 to 10 carbon atoms, and k is an integer of 0 or 1 to 10.

The average molecular weight of the copolymer of the binder resin represented by the general formula (1) is 2,000 to 50,000, the dispersion degree is 1.0 to 5.0, the acidity should be adjusted between 30 to 400 KOHmg / g, preferably the binder resin The average molecular weight of is adjusted to 5,000 to 40,000, the dispersity is 1.6 to 3.0, the acidity is between 50 to 150 KOHmg / g.

In addition, in the general formula 1, using one selected from an alkyl group or a hydroxyalkyl group having 2 to 16 carbon atoms in Y ¹ helps to improve adhesion, and in Y ² , a bulky alicyclic structure is provided. By adding the overcoat material on the substrate and the solvent is volatilized there is an effect of improving the residual film ratio of the remaining coating film.

Another resin used in the present invention is characterized by using a copolymer comprising a combination of a monomer having a benzyl group and / or a phenyl group, a monomer having a carboxylic acid and a monomer having a double bond in the structure of the following general formula (2) There is this.

[Formula 2]

In Formula 2, substituent A is benzyl methacrylate, styrene, styrene, alpha-methyl styrene, isobonyl acrylate, isobonyl methacrylate. B is methacrylic acid, C is glycidyl methacrylate (Glycidyl Methacrylate), hydroxyethyl methacrylate (Hydroxyethyl Methacrylate), dimethylamino methacrylate (Dimethylamino Methacrylate), It is 1 type chosen from acryl amide. The general formula 2 described above is represented by the formulas (2-I) to (2-xx) according to the structures of the substituents A, B and C.

The average molecular weight of the copolymer of the binder resin represented by the general formula 2 is 2,000 to 100,000, the dispersion degree is 1.0 to 5.0, the acidity should be adjusted between 30 to 400 KOHmg / g, preferably a binder resin copolymer The average molecular weight of is 5,000 to 60,000, the dispersion degree is 1.6 to 3.0, the acidity is synthesized by adjusting between 50 to 150 KOHmg / g. When the resist composition prepared by using the two binders of Formula 1 and Formula 2 described above is rotated on a glass plate and then irradiated with ultraviolet rays using a mask and developed with an alkali developer, a thin film having a desired pattern may be manufactured. And no defects such as residues are observed after development. In addition, in Formula 2, the use of one selected from benzyl and / or phenyl groups helps to improve adhesion and can maintain excellent resolution and pattern stability even after coating and developing a resist material on a substrate.

In general, the binder resin is a copolymer prepared by a radical reaction, which is a combination of a monomer containing an aromatic group, a monomer containing a carboxylic acid, and a monomer having a double bond. When the binder resin of the general formula 1 is used alone, the double bond of the binder increases the compatibility with the multifunctional monomer and participates in the photopolymerization to increase the strength of the pattern but the adhesion with the glass is poor and the pattern is brittle (brittle) There was a weak problem in the lateral pressure.

When using a binder resin represented by Formula 1 and Formula 2 to solve the above problems, the strengths and weaknesses of Formula 1 and Formula 2 are compensated for each other, thereby increasing the strength of the pattern and adhesion to the glass surface. It improves, increases compatibility with multifunctional monomers and whitening disappears.

The multifunctional monomer is a polymerizable compound having an ethylenically unsaturated bond used in a known photosensitive composition. Ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene oxide groups, and trimethylolpropane Di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, and propylene glycol di (meth) having 2 to 14 propylene oxide groups Compounds obtained by esterifying polyhydric alcohols such as acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and α, β-unsaturated carboxylic acid; Compounds obtained by adding (meth) acrylic acid to glycidyl group-containing compounds such as trimethylolpropanetriglycidyl ether acrylic acid adduct and bisphenol A diglycidyl ether acrylic acid adduct; ester compounds of a compound having a hydroxyl group and an ethylenically unsaturated bond, such as a phthalic acid diester of β-hydroxyethyl (meth) acrylate, a toluene diisocyanate adduct of β-hydroxyethyl (meth) acrylate, or a polyhydric carboxylic acid, or Adducts with polyisocyanates; It is preferable to use one or two or more selected from (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate. effective.

By appropriately adjusting the composition of the multifunctional monomer and the binder resin, which are polymerizable compounds having an ethylenically unsaturated bond, it is possible to produce a resist composition for overcoat that can maintain high heat resistance, high transparency, high flattening rate and pattern stability.

As photoinitiators, acetophenone-based or benzophenone-based compounds are generally used. When the photoinitiator itself has a color, it acts to reduce transparency. Thus, by using a photosensitive initiator having appropriate sensitivity in the wavelength range used and having no color in the photoinitiator itself, High transparency can be achieved. In general, the photoinitiator of the crosslinking reaction using the acrylic multifunctional monomer is used according to the wavelength of the ultraviolet rays used. Since the mercury lamp, which is the most widely used ultraviolet ray, has a wavelength in the range of 310 to 420 nm, a photoinitiator that generates radicals in this wavelength range Use

As such photoinitiators, it is preferable to use benzophenones and triazines such as Irgacure 369, Irgacure 907, and EPD / BMS mixed system. Benzophenone, phenylbiphenyl ketone, 1-hydroxy-1-benzoylcyclohexane, benzyl, benzyldimethyl ketal, 1-benzyl-1-dimethylamino-1- (4-morpholino-benzoyl) propane, 2-morpholinyl-2- (4-methylmercapto) benzoylpropane, thioxanthone, 1-chloro-4- hydroxythioxanthone, isopropyl thioxanthone, diethyl thioxanthone, ethyl anthraquinone, 4-benzoyl 4-methyldiphenylsulfide, benzoin butyl ether, 2-hydroxy-2-benzoylpropane, 2-hydroxy-2- (4-isopropyl) benzoylpropane, 4-butylbenzoyltrichloromethane, 4-phenoxy Cybenzoyldichloromethane, methyl benzoyl formate, 1,7-bis (9-acridinyl) heptane, 9-n-butyl-3,6-bis (2-morpholino-isobutyloyl) carbazole, 2 -Methyl-4,6-bis (trichloromethyl) -s-triazine, 2-phenyl-4,6-bis (trichloromethyl) -s-triazine, 2-naphthyl-4,6-bis ( Trichloromethyl) -s-triazine and the like.

In order to increase the transparency and minimize the dose, it is more effective to use benzophenone-based or triazine-based photoinitiators alone or in combination and 0.1 to 50% by weight based on the total resin solids.

Silicone-based additives having epoxy groups have the effect of improving adhesion and heat resistance properties after curing, and (3-glycidoxypropyl) trimethoxy (ethoxy) silane (3-glycidoxypropyl) methyldimethoxy ( Methoxy) silane, (3-glycidoxypropyl) dimethylmethoxy (ethoxy) silane, 3,4-epoxybutyltrimethoxy (ethoxy) silane, 2- (3,4-epoxycyclohexyl) It is preferable to use ethyl trimethoxy (ethoxy) silane and the like.

The organic solvent used in the binder resin is used not only to add and mix the binder resin, the multifunctional monomer and other compounds to dissolve it, but also to obtain excellent coating properties and a transparent thin film, and is compatible with the binder resin, the multifunctional monomer and other compounds. It is effective to use this excellent organic solvent. As a solvent used for the above purpose, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate (EEP), ethyl lactate, propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether , Propylene glycol propyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol methyl (or ethyl) acetate, acetone, methyl isobutyl ketone, cyclohexanone, dimethyl formamide (DMF), N, N- Dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), γ-butyrolactone, diethyl ether, ethylene glycol dimethyl ether, diglyme, tetrahydrofuran (THF), methanol, ethanol, propanol Choose from iso-propanol, methyl (or ethyl) cellosolve, diethylene glycol methyl (or ethyl) ether, dipropylene glycol methyl ether, toluene, xylene, hexane, heptane, octane Use a solvent mixture of one or two more.

In addition, the resist composition for overcoat is effective to adjust the viscosity to 2 to 20 cps in order to control the coating property and the solid content, preferably to adjust to 5 to 15 cps pinhole (pin-) of the thin film after coating no holes) and more advantageous for controlling the thickness of thin films.

The resist composition for overcoat of this invention can contain compatible additives, such as surfactant, a storage stabilizer, a sensitizer, a striation inhibitor, a plasticizer, as needed.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. These examples are only for illustrating the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not limited to these examples according to the gist of the present invention.

Example of Representative Overcoat Resist Composition of the Present Invention : A binder resin solution represented by Formula 1 and Formula 2 and dipentaerythritol hexa / penta-acrylate, which are multifunctional monomers, are formed in a reaction A photoinitiator Irgacure 369, (3-glycidoxypropyl) trimethoxy (ethoxy) silane, a known photosensitizer, a thermal polymerization inhibitor, an antifoaming agent, corresponding to 0.1 to 3% by weight of the total resin solids, Compositions having components such as leveling agents are sequentially added, stirred at room temperature, and then a solvent is added to adjust the viscosity of the resist composition to 5-15 cps.

In the examples, the binder resin is represented by the general formula (1) and the formula (I) to the formula (XX) represented by the formula (1-I) to the formula (1-XX), the general formula 2 and each substituent A, B and According to the structure of C it is represented by the formula (2-I) to the formula (2-XX).

Comparative Example of Representative Overcoat Resist Composition of the Present Invention A resist composition for overcoat was prepared in the same composition and method as in Example except that the following General Formula 3 was used.

[Formula 3]

Where p is 0 <p / p + q ≦ 1, q is 0 <q / p + q ≦ 1 and r is (1-p-q).

(1 kg standard)

In the amount of solvent added, the balance means to add the remaining parts except for the part including the binder resin, the multifunctional monomer, the silane epoxy compound, the photoinitiator and the additive at 1 kg.

In the above Examples and Comparative Examples, the resist composition was evaluated on a substrate such as a silicon wafer or a glass plate, and performance evaluations of thermal properties, UV transmittance, residual film ratio, pattern formation, and the like of the resist composition were performed. It is shown in Table 1 below.

(1) Thermal characteristic investigation

In order to evaluate the thermal properties of the resist composition for overcoat, the pyrolysis temperature was measured using a thermogravimetric analysis (TGA), and the temperature at which 5% of the initial weight was reduced was compared as the initial decomposition temperature.

(2) UV transmittance

The resist composition was applied onto the substrate using a spin coater at a speed of 500 rpm for 20 seconds, then prebaked at 60 ° C. for 30 seconds, cured at 350 nm for 20 seconds, and then postbaked at 110 ° C. for 60 seconds. Was carried out to form a resist film, and the transmittance was measured by transmitting UV.

(3) residual film rate

The thickness after the spin coating of the resist composition for overcoat on the substrate and the thickness ratio of the film formed after removing the solvent are shown.

(4) pattern formation

The silicon wafer in which the resist pattern was formed is cut from the vertical direction of the line pattern, and the result observed by the electron microscope in the cross-sectional direction of the pattern is shown. The pattern side wall was erected at an angle of 80 degrees or more with respect to the substrate, the film was not reduced, and it was determined as 'good', and the reduction of the film was judged as 'film'.

(5) adhesion

The line pattern of the silicon wafer on which the resist pattern is formed is divided into 100 parts and peeled off in a vertical direction using a tape, and it is judged as 'bad' that the peeling of the pattern is recognized as 'good' that the pattern has not been peeled off. It was.

As can be seen from Table 1, the resist composition for overcoat using a mixture of two kinds of binder resins of Formula 1 and Formula 2 of the present invention is not only excellent in heat resistance, transparency, residual film ratio, and flatness, but also strength of pattern. Increased and adhesion to the glass surface was improved, and pattern stability was also found to be very good.

FIG. 1 shows a schematic view of using a resist composition for overcoat using a mixture of two kinds of binder resins represented by Formula 1 and Formula 2 as an overcoat of a color filter in a TFT-LCD. FIG. 2 shows stable thermal properties up to 255 ° C. by thermogravimetric decomposition of an overcoat resist after UV curing of the resist composition according to Example 1, and FIG. 3 shows a photoinitiator of Irgacure369 as an overcoat resist after UV curing of the resist composition of Example 1 When used, it was found that the transmittance of more than 95% at 400nm. 4 shows excellent pattern formation in the pattern formation photograph of the resist composition according to Example 1. FIG.

As described above, according to the present invention, a resist composition for overcoat using a mixture of two kinds of binder resins of Formula 1 and Formula 2 is required for overcoat by changing the composition of the two kinds of binder resins or the composition ratio of the multifunctional monomers. It is possible to control the physical properties, and to form a pattern by curing the overcoat resist composition prepared in the present invention by ultraviolet rays and developed with an alkali developer, the strength of the pattern is increased and adhesion to the glass surface is improved Excellent heat resistance, transparency, residual film ratio, flatness and pattern stability can be easily realized, which can be used for overcoat of color filters in TFT-LCDs.

Claims (8)

Multifunctional monomers corresponding to 50 to 500% by weight of the total resin solids are added to the two kinds of binder resins represented by the following general formulas (1) and (2); 0.1-50% by weight of photoinitiator of the total resin solids; Silicone-based compound containing 0.1 to 10% by weight of the epoxy group of the total resin solids; A composition in which components such as a known photosensitizer, a thermal polymerization inhibitor, an antifoaming agent, and a leveling agent corresponding to 0.1 to 3% by weight of the total resin solids are mixed; And it is prepared by adding a solvent, the resist composition for overcoat. [Formula 1] X represents a hydrogen atom or a methyl group, Y ¹ represents an alkyl group or a hydroxyalkyl group having 2 to 16 carbon atoms, and Y ² represents the following formulas (I) to (XX). In formulas (I) to (XX), R ₁ is hydrogen or a methyl group, R ₂ is an alkylene group having 1 to 10 carbon atoms, R ₃ is a residual group of hydrocarbon having 1 to 10 carbon atoms , R ₄ is hydrogen or a methyl group, R ₅ is an alkylene group with from 1 to 10 carbon atoms, and k is an integer of 0 or 1 to 10. [Formula 2] In Formula 2, the substituent A is benzyl methacrylate, styrene, styrene, alpha-methyl styrene, isobonyl acrylate, isobonyl methacrylate B is methacrylic acid, C is glycidyl methacrylate (Glycidyl Methacrylate), hydroxyethyl methacrylate (Hydroxyethyl Methacrylate), dimethylamino methacrylate (Dimethylamino Methacrylate), It is 1 type chosen from acryl amide. The method of claim 1, The average molecular weight of the copolymer which is the binder resin represented by the general formula (1) is 5,000 to 40,000, the dispersity is 1.6 to 3.0, the acidity is prepared using a 50 to 150 KOHmg / g, the resist composition for overcoat . The method of claim 1, The average molecular weight of the copolymer of the binder resin represented by the general formula (2) is 5,000 to 60,000, the dispersity is 1.6 to 3.0, the acidity is prepared using a 50 to 150 KOHmg / g, characterized in that the resist composition for overcoat . The method of claim 1, The multifunctional monomer which is a polymerizable compound having an ethylenically unsaturated bond includes ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate having 2 to 14 ethylene oxide groups, trimethylolpropanedi (meth) acrylate, Trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, propylene glycol di (meth) acrylate with 2 to 14 propylene oxide groups, dipentaerythritol penta Compounds obtained by esterifying polyhydric alcohols such as (meth) acrylate and dipentaerythritol hexa (meth) acrylate with α, β-unsaturated carboxylic acid; Compounds obtained by adding (meth) acrylic acid to glycidyl group-containing compounds such as trimethylolpropanetriglycidyl ether acrylic acid adduct and bisphenol A diglycidyl ether acrylic acid adduct; ester compounds of a compound having a hydroxyl group and an ethylenically unsaturated bond, such as a phthalic acid diester of β-hydroxyethyl (meth) acrylate, a toluene diisocyanate adduct of β-hydroxyethyl (meth) acrylate, or a polyhydric carboxylic acid, or Adducts with polyisocyanates; Prepared by mixing one or two or more selected from (meth) acrylic acid alkyl esters such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate Resist composition for overcoat, characterized in that. The method of claim 1, The photoinitiator is a resist composition for overcoat, characterized in that prepared by mixing one or two or more selected from benzophenone-based or triazine-based photoinitiator. The method of claim 1, Silicone-based additives having epoxy groups include (3-glycidoxypropyl) trimethoxy (ethoxy) silane (3-glycidoxypropyl) methyldimethoxy (ethoxy) silane, (3-glycidoxypropyl) dimethyl Methoxy (ethoxy) silane, 3,4-epoxybutyltrimethoxy (ethoxy) silane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy (ethoxy) silane or Resist composition for overcoat, characterized in that prepared by mixing two or more. The method of claim 1, As solvent, ethyl acetate, butyl acetate, methyl methoxy propionate, ethyl ethoxy propionate (EEP), ethyl lactate, propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether, propylene glycol propyl ether, methyl Cellosolve acetate, ethyl cellosolve acetate, diethylene glycol methyl (or ethyl) acetate, acetone, methyl isobutyl ketone, cyclohexanone, dimethyl formumamide (DMF), N, N-dimethylacetamide (DMAc), N-methylpyrrolidinone (NMP), g-butyrolactone, diethyl ether, ethylene glycol dimethyl ether, diglyme, tetrahydrofuran (THF), methanol, ethanol, propanol, iso-propanol, methyl (or ethyl) One or two or more selected from cellosolve, diethylene glycol methyl (or ethyl) ether, dipropylene glycol methyl ether, toluene, xylene, hexane, heptane, and octane Overcoat resist composition characterized in that the tank. The method of claim 1, Resist composition for overcoat, characterized in that the viscosity of the mixed composition is in the range of 5 to 15 cps.